Generate Dynamic Favicon in PHP

Gmail has just launched small but really useful feature in Gmail Labs. Dynamic Favicon showing unread email counts directly in your browser tab icon. If your browser window has lots and lots of tabs open at anytime, this might be really a wonderful feature that lets user know of any unread item. Here is a small and powerful script in PHP that lets you create your own Dynamic favicon. We will use PHP GD library to manipulate the favicon image and add text into it. Below is the simple script that reads a favicon image add add some text character on it.

<pre>
//Read the favicon template from favicon.png
//file from current directory
$im = imagecreatefrompng("favicon.png");
//$im = imagecreatefromjpg("favicon.jpg");   //using this function to load favicon of jpeg type
//$im = imagecreatefrombmp("favicon.bmp"); //using this function to load favicon of bmp type
 
/* Read the character which needs to be added in favicon from
 * get request
 */
if(isset($_GET['char']) && !empty($_GET['char'])) {
    $string = $_GET['char'];
} else {
    /* If no character is specified; add some default value */
    $string = 'V';
}
 
/* background color for the favicon */
$bg = imagecolorallocate($im, 255, 255, 255);
 
/* foreground (font) color for the favicon */
$black = imagecolorallocate($im, 0, 0, 0);
 
/* Write the character in favicon
 * arguements: image, fontsize, x-coordinate,
 *              y-coordinate, characterstring, color
 */
imagechar($im, 2, 5, 1, $string, $black);
 
header('Content-type: image/png');
 
imagepng($im);

</pre>